STRUCTURE FOR IMPROVED GAS ACTIVATION FOR CROSS-FLOW TYPE THERMAL CVD CHAMBER

摘要

Embodiments described herein generally relate to a processing apparatus having a preheat ring for preheating the process gas. The preheat ring is disposed on a ring support. The preheat ring may have a segment adjacent a process gas inlet. The segment includes a top surface, and the top surface includes features to increase the surface area. In one embodiment, the feature is a plurality of protrusions. In another embodiment, the feature is a plurality of linear fins. In another embodiment, the preheat ring includes a first sub ring and a second sub ring disposed on the first sub ring, wherein the features are located on one segment of the second sub ring.